热裂解-气相色谱-质谱法快速筛查和定量分析乳与乳制品中的4种微塑料

Rapid screening and quantitative analysis of 4 kinds of microplastics in milk and dairy products by pyrolysis-gas chromatography-mass spectrometry

中文关键词:  热裂解-气相色谱-质谱法  乳与乳制品  微塑料

英文关键词:pyrolysis-gas chromatography mass spectrometry  milk and dairy products  microplastics

中文摘要:

      目的 建立热裂解-气相色谱-质谱法(pyrolysis-gas chromatography mass spectrometry, PY-GC-MS)快速筛查和定量分析乳与乳制品中的4种微塑料(microplastics, MPs)的方法。方法 以聚碳酸酯(polycarbonate, PC)、聚对苯二甲酸乙二醇酯(polyethylene terephthalate, PET)、聚酰胺6 (polyamide 6, PA6)和聚酰胺66 (polyamide 66, PA66) 4种微塑料粒子为例, 采用红外光谱和粒度分析对微塑料形貌进行表征。考察进样模式、裂解温度对裂解效果的影响, 并对4种微塑料的特征定量峰进行比较, 最终选择单击式裂解模式, 裂解温度600℃, 4种微塑料的特征物质分别为双酚A、对苯二甲酸-2-苯甲酰氧基乙酯乙烯酯、己内酰胺和环戊酮。验证裂解方法的稳定性和特异性, 利用高温裂解产生的特征碎片离子进行定量分析。结果 本方法对4种微塑料检测的线性范围为2~64 μg与4~64 μg (PET), 检出限为0.1~1.2 μg, 定量限为0.3~4.0 μg, 平均加标回收率为79.5%~96.0%, 精密度为1.74%~10.80%。结论 本方法适用于乳与乳制品中微塑料的检测, 也可以进一步优化条件应用到其他类型的微塑料检测过程, 作为微塑料浓度检测标准制定的参考方法。

英文摘要:

      Objective To establish a method for the rapid screening and quantitative analysis of microplastics (MPs) in milk and dairy products by pyrolysis-gas chromatography-mass spectrometry (PY-GC-MS). Methods Taking polycarbonate (PC), polyethylene terephthalate (PET), polyamide 6 (PA6) and polyamide 66 (PA66) as examples, the morphology of the MPs was characterized by infrared spectrometer and laser particle size analyzer. The effects of injection mode and pyrolysis temperature on the pyrolysis effect were investigated, and the characteristic quantitative peaks of 4 kinds of MPs were compared. Finally, the one-click cracking mode was selected. The cracking temperature was 600℃, and the characteristic substances of the 4 kinds of MPs were bisphenol A, terephthalic acid-2-dibenzoyloxyethyl ester, caprolactam and cyclopentanone, respectively. The stability and specificity of the thermal decomposition method were verified. The characteristic fragment ions produced by the thermal decomposition were separated by chromatography and identified by mass spectrometry for quantitative analysis. Results There were good linearities for the 4 kinds of MPs in the range of 2?64 μg and 4-64 μg (PET). The limits of detection of the 4 kinds of MPs were in the range of 0.1?1.2 μg and the limits of quantitation were in the range of 0.3?4.0 μg. The average spiked recoveries of the 4 kinds of MPs were ranged from 79.5% to 96.0%, with relative standard deviations of 1.74%?10.80%. Conclusion This method is applicable to the detection of microplastics in milk and dairy products, and can also be used to further optimize the conditions for other types of microplastics detection processes, as a reference method for formulating microplastics concentration detection standards.